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The OWL Working Group intends to make OWL 2 be a superset of OWL 1, except for a limited number of situations where we believe the impact will be minimal. This means that OWL 2 will be backward compatible, and creators of OWL 1 documents need only move to OWL 2 when they want to make use of OWL 2 features. More details and advice concerning migration from OWL 1 to OWL 2 will be in future drafts.
The major change to this document since the version of 11 April 2008 reflects the major revamping of the functional syntax to disallow punning between classes and datatypes and between object, data, and annotation properties and to include mapping for new features such as keys. Some minor changes were made to reflect changes in the Functional Syntax.
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Contents 
This document provides mappings by means of which every OWL 2 ontology in the functionalstyle syntax [OWL 2 Specification] can be mapped into RDF triples and back without any change in the formal meaning of the ontology. More precisely, let O be any OWL 2 ontology in functionalstyle syntax, let T(O) be the set of RDF triples obtained by transforming O into RDF triples as specified in Section 2, and let O' be the OWL 2 ontology in functionalstyle syntax obtained by applying the reverse transformation from Section 3 to T(O); then, O and O' are logically equivalent — that is, they have exactly the same set of models.
The RDF syntax of OWL 2 is backwardscompatible with that of OWL DL: every OWL DL ontology in RDF syntax can be mapped into a valid OWL 2 ontology using the reversetransformation from Section 3 such that the resulting OWL 2 ontology has exactly the same set of models as the original OWL DL ontology.
The syntax for triples used in this document is the one used in the RDF Semantics [RDF Semantics]. Full URIs are abbreviated using the namespaces from the OWL 2 Specification [OWL 2 Specification].
The following notation is used throughout this document for referring to parts of RDF graphs:
The italicized keywords MUST, MUST NOT, SHOULD, SHOULD NOT, and MAY specify certain aspects of the normative behavior of OWL 2 tools, and are interpreted as specified in RFC 2119 [RFC 2119].
This section defines a mapping of an OWL 2 ontology O in functionalstyle syntax into a set of RDF triples T(O). The mapping is presented in three parts. Section 2.1 shows how to translate axioms that do not contain annotations, Section 2.2 shows how to translate annotations, and Section 2.3 shows how to translate axioms containing annotations.
Table 1 presents the operator T that maps an OWL 2 ontology O in functionalstyle syntax into a set of RDF triples T(O), provided that no axiom in O is annotated. The mapping is defined recursively, i.e., the mapping of a construct often depends on the mappings of its subconstructs, but in a slightly unusual way. If the mapping of a construct refers to the mapping of a subconstruct, then the triples generated by the recursive invocation of T are added to the graph under construction, and its main node is used in place of the invocation itself.
The definition of the operator T uses the operator TANN in order to translate annotations. The operator TANN is defined in Section 2.2. It takes an annotation and an URI reference or a blank node and produces the triples that attach the annotation to the supplied object.
In the mapping, each generated blank node (i.e., each blank node that does not correspond to an anonymous individual) is fresh in each application of a mapping rule. Furthermore, the following conventions are used in this section to denote different syntactic parts of OWL 2 ontologies:
In this section, T(SEQ y_{1} ... y_{n}) denotes the translation of a sequence of objects from the functionalstyle syntax into an RDF list, as shown in Table 1.
FunctionalStyle Syntax S  Triples Generated in an Invocation of T(S)  Main Node of T(S) 

SEQ  rdf:nil  
SEQ y_{1} ... y_{n}  _:x rdf:first T(y_{1}) _:x rdf:rest T(SEQ y_{2} ... y_{n}) 
_:x 
Ontology( ontologyURI [ versionURI ] Import( importedOntologyURI_{1} ) ... Import( importedOntologyURI_{k} ) annotation_{1} ... annotation_{m} axiom_{1} ... axiom_{n} ) 
ontologyURI rdf:type owl:Ontology [ ontologyURI owl:versionInfo versionURI ] ontologyURI owl:imports importedOntologyURI_{1} ... ontologyURI owl:imports importedOntologyURI_{k} TANN(annotation_{1},ontologyURI) ... TANN(annotation_{m},ontologyURI) T(axiom_{1}) ... T(axiom_{n}) 
ontologyURI 
Ontology( Import( importedOntologyURI_{1} ) ... Import( importedOntologyURI_{k} ) annotation_{1} ... annotation_{m} axiom_{1} ... axiom_{n} ) 
_:x rdf:type owl:Ontology _:x owl:imports importedOntologyURI_{1} ... _:x owl:imports importedOntologyURI_{k} TANN(annotation_{1},_:x) ... TANN(annotation_{m},_:x) T(axiom_{1}) ... T(axiom_{n}) 
_:x 
C  C  
Class( C )  C  
DT  DT  
Datatype( DT )  DT  
OP  OP  
ObjectProperty( OP )  OP  
DP  DP  
DataProperty( DP )  DP  
AP  AP  
AnnotationProperty( AP )  AP  
a  a  
NamedIndividual( *:a )  *:a  
lt  lt  
Declaration( Datatype( DT ) )  T(DT) rdf:type rdfs:Datatype  
Declaration( Class( C ) )  T(C) rdf:type owl:Class  
Declaration( ObjectProperty( OP ) )  T(OP) rdf:type owl:ObjectProperty  
Declaration( DataProperty( DP ) )  T(DP) rdf:type owl:DatatypeProperty  
Declaration( AnnotationProperty( AP ) )  T(AP) rdf:type owl:AnnotationProperty  
Declaration( NamedIndividual( *:a ) )  T(*:a) rdf:type owl:NamedIndividual  
InverseOf( OP )  _:x owl:inverseOf T(OP)  _:x 
ComplementOf( DR )  _:x rdf:type rdfs:Datatype _:x owl:datatypeComplementOf T(DR) 
_:x 
OneOf( lt_{1} ... lt_{n} )  _:x rdf:type rdfs:Datatype _:x owl:oneOf T(SEQ lt_{1} ... lt_{n}) 
_:x 
DatatypeRestriction( DT f_{1} lt_{1} ... f_{n} lt_{n} ) 
_:x rdf:type rdfs:Datatype _:x owl:onDatatype T(DT) _:x owl:withRestrictions T(SEQ _:y_{1} ... _:y_{n}) _:y_{1} f_{1} lt_{1} ... _:y_{n} f_{n} lt_{n} 
_:x 
IntersectionOf( CE_{1} ... CE_{n} )  _:x rdf:type owl:Class _:x owl:intersectionOf T(SEQ CE_{1} ... CE_{n}) 
_:x 
UnionOf( CE_{1} ... CE_{n} )  _:x rdf:type owl:Class _:x owl:unionOf T(SEQ CE_{1} ... CE_{n}) 
_:x 
ComplementOf( CE )  _:x rdf:type owl:Class _:x owl:complementOf T(CE) 
_:x 
OneOf( a_{1} ... a_{n} )  _:x rdf:type owl:Class _:x owl:oneOf T(SEQ a_{1} ... a_{n}) 
_:x 
SomeValuesFrom( OPE CE )  _:x rdf:type owl:Restriction _:x owl:onProperty T(OPE) _:x owl:someValuesFrom T(CE) 
_:x 
AllValuesFrom( OPE CE )  _:x rdf:type owl:Restriction _:x owl:onProperty T(OPE) _:x owl:allValuesFrom T(CE) 
_:x 
HasValue( OPE a )  _:x rdf:type owl:Restriction _:x owl:onProperty T(OPE) _:x owl:hasValue T(a) 
_:x 
ExistsSelf( OPE )  _:x rdf:type owl:SelfRestriction _:x owl:onProperty T(OPE) 
_:x 
MinCardinality( n OPE )  _:x rdf:type owl:Restriction _:x owl:minCardinality "n"^^xsd:nonNegativeInteger _:x owl:onProperty T(OPE) 
_:x 
MinCardinality( n OPE CE )  _:x rdf:type owl:Restriction _:x owl:minQualifiedCardinality "n"^^xsd:nonNegativeInteger _:x owl:onProperty T(OPE) _:x owl:onClass T(CE) 
_:x 
MaxCardinality( n OPE )  _:x rdf:type owl:Restriction _:x owl:maxCardinality "n"^^xsd:nonNegativeInteger _:x owl:onProperty T(OPE) 
_:x 
MaxCardinality( n OPE CE )  _:x rdf:type owl:Restriction _:x owl:maxQualifiedCardinality "n"^^xsd:nonNegativeInteger _:x owl:onProperty T(OPE) _:x owl:onClass T(CE) 
_:x 
ExactCardinality( n OPE )  _:x rdf:type owl:Restriction _:x owl:cardinality "n"^^xsd:nonNegativeInteger _:x owl:onProperty T(OPE) 
_:x 
ExactCardinality( n OPE CE )  _:x rdf:type owl:Restriction _:x owl:qualifiedCardinality "n"^^xsd:nonNegativeInteger _:x owl:onProperty T(OPE) _:x owl:onClass T(CE) 
_:x 
SomeValuesFrom( DPE DR )  _:x rdf:type owl:Restriction _:x owl:onProperty T(DPE) _:x owl:someValuesFrom T(DR) 
_:x 
SomeValuesFrom( DPE_{1} ... DPE_{n} DR ), n ≥ 2  _:x rdf:type owl:Restriction _:x owl:onProperties T(SEQ DPE_{1} ... DPE_{n}) _:x owl:someValuesFrom T(DR) 
_:x 
AllValuesFrom( DPE DR )  _:x rdf:type owl:Restriction _:x owl:onProperty T(DPE) _:x owl:allValuesFrom T(DR) 
_:x 
AllValuesFrom( DPE_{1} ... DPE_{n} DR ), n ≥ 2  _:x rdf:type owl:Restriction _:x owl:onProperties T(SEQ DPE_{1} ... DPE_{n}) _:x owl:allValuesFrom T(DR) 
_:x 
HasValue( DPE lt )  _:x rdf:type owl:Restriction _:x owl:onProperty T(DPE) _:x owl:hasValue T(lt) 
_:x 
MinCardinality( n DPE )  _:x rdf:type owl:Restriction _:x owl:minCardinality "n"^^xsd:nonNegativeInteger _:x owl:onProperty T(DPE) 
_:x 
MinCardinality( n DPE DR )  _:x rdf:type owl:Restriction _:x owl:minQualifiedCardinality "n"^^xsd:nonNegativeInteger _:x owl:onProperty T(DPE) _:x owl:onDataRange T(DR) 
_:x 
MaxCardinality( n DPE )  _:x rdf:type owl:Restriction _:x owl:maxCardinality "n"^^xsd:nonNegativeInteger _:x owl:onProperty T(DPE) 
_:x 
MaxCardinality( n DPE DR )  _:x rdf:type owl:Restriction _:x owl:maxQualifiedCardinality "n"^^xsd:nonNegativeInteger _:x owl:onProperty T(DPE) _:x owl:onDataRange T(DR) 
_:x 
ExactCardinality( n DPE )  _:x rdf:type owl:Restriction _:x owl:cardinality "n"^^xsd:nonNegativeInteger _:x owl:onProperty T(DPE) 
_:x 
ExactCardinality( n DPE DR )  _:x rdf:type owl:Restriction _:x owl:qualifiedCardinality "n"^^xsd:nonNegativeInteger _:x owl:onProperty T(DPE) _:x owl:onDataRange T(DR) 
_:x 
SubClassOf( CE_{1} CE_{2} )  T(CE_{1}) rdfs:subClassOf T(CE_{2})  
EquivalentClasses( CE_{1} ... CE_{n} )  T(CE_{1}) owl:equivalentClass
T(CE_{2}) ... T(CE_{n1}) owl:equivalentClass T(CE_{n}) 

DisjointClasses( CE_{1} CE_{2} )  T(CE_{1}) owl:disjointWith T(CE_{2})  
DisjointClasses( CE_{1} ... CE_{n} ), n > 2  _:x rdf:type owl:AllDisjointClasses _:x owl:members T(SEQ CE_{1} ... CE_{n}) 

DisjointUnion( C CE_{1} ... CE_{n} )  T(C) owl:disjointUnionOf T(SEQ CE_{1} ... CE_{n})  
SubPropertyOf( OPE_{1} OPE_{2} )  T(OPE_{1}) rdfs:subPropertyOf T(OPE_{2})  
SubPropertyOf( PropertyChain( OPE_{1} ... OPE_{n} ) OPE )  _:x rdfs:subPropertyOf T(OPE) _:x owl:propertyChain T(SEQ OPE_{1} ... OPE_{n}) 

EquivalentProperties( OPE_{1} ... OPE_{n} )  T(OPE_{1}) owl:equivalentProperty
T(OPE_{2}) ... T(OPE_{n1}) owl:equivalentProperty T(OPE_{n}) 

DisjointProperties( OPE_{1} OPE_{2} )  T(op_{1}) owl:propertyDisjointWith T(op_{2})  
DisjointProperties( OPE_{1} ... OPE_{n}), n > 2  _:x rdf:type owl:AllDisjointProperties _:x owl:members T(SEQ OPE_{1} ... OPE_{n}) 

PropertyDomain( OPE CE )  T(OPE) rdfs:domain T(CE)  
PropertyRange( OPE CE )  T(OPE) rdfs:range T(CE)  
InverseProperties( OPE_{1} OPE_{2} )  T(OPE_{1}) owl:inverseOf T(OPE_{2})  
FunctionalProperty( OPE )  T(OPE) rdf:type owl:FunctionalProperty  
InverseFunctionalProperty( OPE )  T(OPE) rdf:type owl:InverseFunctionalProperty  
ReflexiveProperty( OPE )  T(OPE) rdf:type owl:ReflexiveProperty  
IrreflexiveProperty( OPE )  T(OPE) rdf:type owl:IrreflexiveProperty  
SymmetricProperty( OPE )  T(OPE) rdf:type owl:SymmetricProperty  
AsymmetricProperty( OPE )  T(OPE) rdf:type owl:AsymmetricProperty  
TransitiveProperty( OPE )  T(OPE) rdf:type owl:TransitiveProperty  
SubPropertyOf( DPE_{1} DPE_{2} )  T(DPE_{1}) rdfs:subPropertyOf T(DPE_{2})  
EquivalentProperties( DPE_{1} ... DPE_{n} )  T(DPE_{1}) owl:equivalentProperty
T(DPE_{2}) ... T(DPE_{n1}) owl:equivalentProperty T(DPE_{n}) 

DisjointProperties( DPE_{1} DPE_{2} )  T(DPE_{1}) owl:propertyDisjointWith T(DPE_{2})  
DisjointProperties( DPE_{1} ... DPE_{n} ), n > 2  _:x rdf:type owl:AllDisjointProperties _:x owl:members T(SEQ DPE_{1} ... DPE_{n}) 

PropertyDomain( DPE CE )  T(DPE) rdfs:domain T(CE)  
PropertyRange( DPE DR )  T(DPE) rdfs:range T(DR)  
FunctionalProperty( DPE )  T(DPE) rdf:type owl:FunctionalProperty  
HasKey( CE PE_{1} ... PE_{n} )  T(CE) owl:hasKey T(SEQ PE_{1} ...
PE_{n}) 

SameIndividual( a_{1} ... a_{n} )  T(a_{1}) owl:sameAs T(a_{2}) ... T(a_{n1}) owl:sameAs T(a_{n}) 

DifferentIndividuals( a_{1} a_{2} )  T(a_{1}) owl:differentFrom T(a_{2})  
DifferentIndividuals( a_{1} ... a_{n} ), n > 2  _:x rdf:type owl:AllDifferent _:x owl:members T(SEQ a_{1} ... a_{n}) 

ClassAssertion( CE a )  T(a) rdf:type T(CE)  
PropertyAssertion( OP a_{1} a_{2} )  T(a_{1}) T(OP) T(a_{2})  
PropertyAssertion( InverseOf( OP ) a_{1} a_{2} )  T(a_{2}) T(OP) T(a_{1})  
NegativePropertyAssertion( OPE a_{1} a_{2} )  _:x rdf:type owl:NegativePropertyAssertion _:x owl:sourceIndividual T(a_{1}) _:x owl:assertionProperty T(OPE) _:x owl:targetIndividual T(a_{2}) 

PropertyAssertion( DPE a lt )  T(a) T(DPE) T(lt)  
NegativePropertyAssertion( DPE a lt )  _:x rdf:type owl:NegativePropertyAssertion _:x owl:sourceIndividual T(a) _:x owl:assertionProperty T(DPE) _:x owl:targetValue T(lt) 

EntityAnnotation( Class( C ) annotation_{1} ... annotation_{m} ) 
TANN(annotation_{1},T(C)) ... TANN(annotation_{m},T(C)) 

EntityAnnotation( Datatype( DT ) annotation_{1} ... annotation_{m} ) 
TANN(annotation_{1},T(DT)) ... TANN(annotation_{m},T(DT)) 

EntityAnnotation( ObjectProperty( OP ) annotation_{1} ... annotation_{m} ) 
TANN(annotation_{1},T(OP)) ... TANN(annotation_{m},T(OP)) 

EntityAnnotation( DataProperty( DP ) annotation_{1} ... annotation_{m} ) 
TANN(annotation_{1},T(DP)) ... TANN(annotation_{m},T(DP)) 

EntityAnnotation( AnnotationProperty( AP ) annotation_{1} ... annotation_{m} ) 
TANN(annotation_{1},T(AP)) ... TANN(annotation_{m},T(AP)) 

EntityAnnotation( NamedIndividual( *:a ) annotation_{1} ... annotation_{m} ) 
TANN(annotation_{1},T(*:a)) ... TANN(annotation_{m},T(*:a)) 

AnonymousIndividualAnnotation( _:a annotation_{1} ... annotation_{m} ) 
TANN(annotation_{1},T(_:a)) ... TANN(annotation_{m},T(_:a)) 
The operator TANN, which translates annotations and attaches them to an URI reference or a blank node, is defined in Table 2. Note that Label, Comment, and Deprecated are syntactic abbreviations, so they are not listed in Table 2.
Annotation ann  Triples Generated in an Invocation of TANN(ann,y) 

Annotation( AP elt )  y T(AP) T(elt) 
Annotation( annotation_{1} ... annotation_{n} AP elt ) 
_:x rdf:type owl:Annotation _:x owl:subject y _:x owl:predicate T(AP) _:x owl:object T(etl) TANN(annotation_{1},_:x) ... TANN(annotation_{n},_:x) 
Consider the following entity annotation, which associates a:Peter with a simple label.
EntityAnnotation( NamedIndividual(a:Peter)
Label( "Peter Griffin" )
)
This axiom is translated into the following triple:
a:Peter rdfs:label "Peter
Griffin"^^xsd:string
Consider the following axioms, which associates a:Peter with an annotation containing a nested annotation.
EntityAnnotation( NamedIndividual(a:Peter)
Annotation(
Annotation( a:author
a:Seth_MacFarlane )
rdfs:label "Peter
Griffin"
)
)
This axiom is translated into the following triples:
_:x rdf:type owl:Annotation
_:x owl:subject a:Peter
_:x owl:predicate rdfs:label
_:x owl:object "Peter Griffin"^^xsd:string
_:x a:auhtor a:Seth_MacFarlane
If an axiom ax contains embedded annotations annotation_{1} ... annotation_{m}, its serialization into RDF depends on the type of the axiom. In the following discussion, let ax' be the axiom that is obtained from ax by removing all annotations. Note that the Label and Comment annotations are just abbreviations, so they are serialized into RDF by expanding the abbreviation and then applying the serialization presented here.
If ax' is translated into a single RDF triple s p o, then the axiom ax generates the following triples instead of triple s p o:
_:x rdf:type owl:Axiom
_:x owl:subject s
_:x owl:predicate p
_:x owl:object o
TANN(annotation_{1},_:x)
...
TANN(annotation_{m},_:x)
This is the case for the following axioms: SubClassOf, DisjointClasses with two classes, SubPropertyOf without a property chain as the subproperty expression, PropertyDomain, PropertyRange, InverseProperties, FunctionalProperty, InverseFunctionalProperty, ReflexiveProperty, IrreflexiveProperty, SymmetricProperty, AsymmetricProperty, TransitiveProperty, DisjointProperties with two properties, ClassAssertion, PropertyAssertion, Declaration, and DifferentIndividuals with two individuals.
Consider the following subclass axiom:
SubClassOf( Comment( "Children are people." ) a:Child a:Person )
Without the annotation, the axiom would be translated into the following triple:
a:Child rdfs:subClassOf a:Person
Thus, the annotated axiom is transformed into the following triples:
_:x rdf:type owl:Axiom
_:x owl:subject a:Child
_:x owl:predicate rdfs:subClassOf
_:x owl:object a:Person
_:x rdfs:comment "Children are people."
Axioms DisjointUnion, SubPropertyOf with a subproperty chain, and HasKey are, without annotations, translated into several, and not a single triple. If such such axioms are annotated, then the main triple is subjected to the transformation described above. The other triples — called side triples — are output without any change.
Consider the following subproperty axiom:
SubPropertyOf( Comment( "An aunt is a mother's sister." ) PropertyChain( a:hasMother a:hasSister ) a:hasAunt ) )
Without the annotation, the axiom would be translated into the following triples:
_:y rdfs:subPropertyOf a:hasAunt
_:y owl:propertyChain _:z_{1}
_:z_{1} rdf:first a:hasMother
_:z_{1} rdf:rest _:z_{2}
_:z_{2} rdf:first a:hasSister
_:z_{2} rdf:rest rdf:nil
In order to capture the annotation on the axiom, the first triple plays the role of the main triple for the axiom, so it is represented using a fresh blank node _:x in order to be able to attach the annotation to it.
_:x rdf:type owl:Axiom
_:x owl:subject _:y
_:x owl:predicate rdfs:subPropertyOf
_:x owl:object a:hasAunt
_:x rdfs:comment "An aunt is a mother's sister."
_:y owl:propertyChain _:z_{1}
_:z_{1} rdf:first a:hasMother
_:z_{1} rdf:rest _:z_{2}
_:z_{2} rdf:first a:hasSister
_:z_{2} rdf:rest rdf:nil
Consider the following key axiom:
HasKey( Comment( "SSN uniquely determines a person." ) a:Person a:hasSSN )
Without the annotation, the axiom would be translated into the following triples:
a:Person owl:hasKey _:y
_:y rdf:first a:hasSSN
_:y rdf:rest rdf:nil
In order to capture the annotation on the axiom, the first triple plays the role of the main triple for the axiom, so it is represented using a fresh blank node _:x in order to be able to attach the annotation to it.
_:x rdf:type owl:Axiom
_:x owl:subject a:Person
_:x owl:predicate owl:hasKey
_:x owl:object _:y
_:x rdfs:comment "SSN uniquely determines a person."
_:y rdf:first a:hasSSN
_:y rdf:rest rdf:nil
If the axiom ax' is of type EquivalentClasses, EquivalentProperties, SameIndividual, or EntityAnnotation its translation into RDF can be broken up into several RDF triples (because RDF can only represent binary relations). In this case, each of the RDF triples obtained by the translation of ax' is transformed as described in previous section, and the annotations are repeated for each of the triples obtained in the translation.
Consider the following individual equality axiom:
SameIndividual( Annotation( a:source a:Fox ) a:Meg a:Megan a:Megan_Griffin )
This axiom is first split into the following equalities between pairs of individuals, and the annotation is repeated on each axiom obtained in this process:
SameIndividual( Annotation( a:source a:Fox )
a:Meg a:Megan )
SameIndividual( Annotation( a:source a:Fox )
a:Megan a:Megan_Griffin )
Each of these axioms is now transformed into triples as explained in the previous section:
_:x_{1} rdf:type owl:Axiom
_:x_{1} owl:subject a:Meg
_:x_{1} owl:predicate owl:sameAs
_:x_{1} owl:object a:Megan
_:x_{1} a:source a:Fox
_:x_{2} rdf:type owl:Axiom
_:x_{2} owl:subject a:Megan
_:x_{2} owl:predicate owl:sameAs
_:x_{2} owl:object a:Megan_Griffin
_:x_{2} a:source a:Fox
If the axiom ax' is of type NegativePropertyAssertion, DisjointClasses with more than two classes, DisjointUnion with more than two properties, or DifferentIndividuals with more than two individuals, then its translation already requires introducing a blank node _:x. In such cases, ax is translated by first translating ax' into _:x as shown in Table 1, and then attaching the annotations of ax to _:x.
Consider the following negative property assertion:
NegativePropertyAssertion( Annotation( a:author a:Seth_MacFarlane ) a:brotherOf a:Chris a:Stewie )
Even without the annotation, this axiom would be represented using a blank node. The annotation can readily be attached to this node, so the axiom is transformed into the following triples:
_:x rdf:type owl:NegativePropertyAssertion
_:x owl:sourceIndividual a:Chris
_:x owl:assertionProperty a:brotherOf
_:x owl:targetIndividual a:Stewie
_:x a:author a:Seth_MacFarlane
This section specifies canonical RDF parsing — a process that transforms a set of RDF triples G into an OWL 2 ontology O in functionalstyle syntax, if possible. This process is specified as an instance of canonical parsing, defined in Section 5.9.3 of the OWL 2 Specification [OWL 2 Specification]. It is important to understand that canonical RDF parsing merely defines the result of the transformation. An OWL 2 implementation MAY implement whatever algorithm it chooses; however, the result MUST be structurally equivalent to the result of canonical RDF parsing.
Canonical RDF parsing maintains the following functions that map a URI reference or a blank node x occurring in G into a fragment of the functionalstyle syntax. In particular,
Initially, these functions are undefined for all URIs and blank nodes occurring in G; this is written as CE(x) = ε, DR(x) = ε, OPE(x) = ε, DPE(x) = ε, and AP(x) = ε. The functions are updated as parsing progresses. If at any point in time the following conditions become invalidated, G MUST be rejected as syntactically incorrect.
Firthermore, if there is an attempt to redefine the value of any of these functions for any x (i.e., if a function is not undefined for x and there is an attempt to change the function's value for x), then G MUST be rejected as syntactically incorrect.
The function OPEorDPE is defined as follows:
The following sections contain rules in which triple patterns are matched to G. The following notation is used to denote parts of the patterns that are matched to literals with integer value:
Additional conditions on the pattern are enclosed in curly braces { }. Some patterns use optional parts, which are enclosed in square brackets '[ ]'. If a pattern contains a variable number of triples, the maximal possible subset of G MUST be matched.
The abbreviation T(SEQ y_{1} ... y_{n}) denotes the pattern corresponding to RDF lists, as shown in Table 3. This is similar to the mapping for lists presented in Table 1, but here the abbreviation is used to recognize lists instead of mapping them into RDF.
Sequence S  Triples Corresponding to T(S)  Main Node of T(S) 

SEQ  rdf:nil  
SEQ y_{1} ... y_{n}  _:x rdf:first y_{1} _:x rdf:rest T(SEQ y_{2} ... y_{n}) 
_:x 
First, the ontology header is extracted from G. In particular, if G does not contain a triple whose predicate is rdf:type and object is owl:Ontology, then the ontology header is Ontology( ... ). Otherwise, patterns from Table 4 are matched to G; if no such pattern can be matched in G, or if the pattern can be matched to G in more than one way, the graph G MUST be rejected as syntactically incorrect. Each time a triple pattern is matched, the matched triples are removed from G.
If G contains this pattern...  ...then the ontology header has this form. 

*:x rdf:type owl:Ontology [ *:x owl:versionInfo *:y ] *:x owl:imports z_{1} ... *:x owl:imports z_{k} { The following triple pattern cannot be matched in G: u w *:x u rdf:type owl:Ontology w rdf:type owl:OntologyProperty } 
Ontology( *:x [ *:y ] Import( z_{1} ) ... Import( z_{k} ) ... ) 
_:x rdf:type owl:Ontology _:x owl:imports y_{1} ... _:x owl:imports y_{k} { The following triple pattern cannot be matched in G: u w _:x u rdf:type owl:Ontology w rdf:type owl:OntologyProperty } 
Ontology( Import( y_{1} ) ... Import( y_{k} ) ... ) 
Next, for backwards compatibility with OWL DL, certain redundant triples are removed from G. In particular, if the triple pattern from the lefthand side of Table 5 is matched in G, then the triples on the righthand side of Table 5 are removed from G.
If G contains this pattern...  ...then these triples are removed from G. 

x rdf:type owl:Ontology  x rdf:type owl:Ontology 
x rdf:type owl:Class x rdf:type rdfs:Class 
x rdf:type rdfs:Class 
x rdf:type rdfs:Datatype x rdf:type rdfs:Class 
x rdf:type rdfs:Class 
x rdf:type owl:DataRange x rdf:type rdfs:Class 
x rdf:type rdfs:Class 
x rdf:type owl:Restriction x rdf:type rdfs:Class 
x rdf:type rdfs:Class 
x rdf:type owl:Restriction x rdf:type owl:Class 
x rdf:type owl:Class 
x rdf:type owl:ObjectProperty x rdf:type rdf:Property 
x rdf:type rdf:Property 
x rdf:type owl:FunctionalProperty x rdf:type rdf:Property 
x rdf:type rdf:Property 
x rdf:type owl:InverseFunctionalProperty x rdf:type rdf:Property 
x rdf:type rdf:Property 
x rdf:type owl:TransitiveProperty x rdf:type rdf:Property 
x rdf:type rdf:Property 
x rdf:type owl:DatatypeProperty x rdf:type rdf:Property 
x rdf:type rdf:Property 
x rdf:type owl:AnnotationProperty x rdf:type rdf:Property 
x rdf:type rdf:Property 
x rdf:type owl:OntologyProperty x rdf:type rdf:Property 
x rdf:type rdf:Property 
x rdf:type rdf:List x rdf:first y x rdf:rest z 
x rdf:type rdf:List 
Next, for backwards compatibility with OWL DL, G is modified such that declarations can be properly extracted in the next step. When a triple pattern from the first column of Table 6 is matched in G, the matching triples are replaced in G with the triples from the second column. This matching phase stops when matching a pattern and replacing it as specified does not change G. Note that G is a set and thus cannot contain duplicate triples, so this last condition prevents infinite matches.
If G contains this pattern...  ...then the matched triples are replaced in G with these triples. 

*:x rdf:type owl:OntologyProperty  *:x rdf:type owl:AnnotationProperty 
*:x rdf:type owl:InverseFunctionalProperty  *:x rdf:type owl:ObjectProperty *:x rdf:type owl:InverseFunctionalProperty 
*:x rdf:type owl:TransitiveProperty  *:x rdf:type owl:ObjectProperty *:x rdf:type owl:TransitiveProperty 
*:x rdf:type owl:SymmetricProperty  *:x rdf:type owl:ObjectProperty *:x rdf:type owl:SymmetricProperty 
Finally, the set of declarations Decl(O) is extracted from G according to Table 7. The matched triples are not removed from G — the triples from Table 7 can contain annotations so, in order to correctly parse the annotations, they will be matched again in the step described in Section 3.4.
If G contains this pattern...  ...then this declaration is added to Decl(O). 

*:x rdf:type owl:Class  Declaration( Class( *:x ) ) 
*:x rdf:type rdfs:Datatype  Declaration( Datatype( *:x ) ) 
*:x rdf:type owl:ObjectProperty  Declaration( ObjectProperty( *:x ) ) 
*:x rdf:type owl:DatatypeProperty  Declaration( DataProperty( *:x ) ) 
*:x rdf:type owl:AnnotationProperty  Declaration( AnnotationProperty( *:x ) ) 
*:x rdf:type owl:NamedIndividual  Declaration( NamedIndividual( *:x ) ) 
_:x rdf:type owl:Axiom _:x owl:subject *:y _:x owl:predicate rdf:type _:x owl:object owl:Class 
Declaration( Class( *:y ) ) 
_:x rdf:type owl:Axiom _:x owl:subject *:y _:x owl:predicate rdf:type _:x owl:object rdfs:Datatype 
Declaration( Datatype( *:y ) ) 
_:x rdf:type owl:Axiom _:x owl:subject *:y _:x owl:predicate rdf:type _:x owl:object owl:ObjectProperty 
Declaration( ObjectProperty( *:y ) ) 
_:x rdf:type owl:Axiom _:x owl:subject *:y _:x owl:predicate rdf:type _:x owl:object owl:DatatypeProperty 
Declaration( DataProperty( *:y ) ) 
_:x rdf:type owl:Axiom _:x owl:subject *:y _:x owl:predicate rdf:type _:x owl:object owl:AnnotationProperty 
Declaration( AnnotationProperty( *:y ) ) 
_:x rdf:type owl:Axiom _:x owl:subject *:y _:x owl:predicate rdf:type _:x owl:object owl:NamedIndividual 
Declaration( NamedIndividual( *:y ) ) 
Next, for each ontology O' imported into O, the ontology header and declarations are determined. If the ontology O' is written in RDF then this is done as above. If the ontology O' is written in some other format then the ontology header and declarations are determined according to the rules appropriate to the ontology format.
The set AllDecl(O) of all declarations is computed by taking the union of the set Decl(O), the sets Decl(O') for each ontology O' imported (directly or indirectly) into O, and the declarations for builtin entities from Table 10 of the OWL 2 Specification [OWL 2 Specification]. The declarations in AllDecl(O) are checked for typing constraints, as specified in Section 5.9.1 of the OWL 2 Specification [OWL 2 Specification]. If the constraints are not satisfied, the graph G MUST be rejected as syntactically incorrect.
Next, the functions CE, DR, OPE, DPE, and AP are initialized as shown in Table 8.
If AllDecl(O) contains this declaration...  ...then perform this assignment. 

Declaration( Class( *:x ) )  CE(*:x) := a class with the URI *:x 
Declaration( Datatype( *:x ) )  DR(*:x) := a datatype with the URI *:x 
Declaration( ObjectProperty( *:x ) )  OPE(*:x) := an object property with the URI *:x 
Declaration( DataProperty( *:x ) )  DPE(*:x) := a data property with the URI *:x 
Declaration( AnnotationProperty( *:x ) )  AP(*:x) := an annotation property with the URI *:x 
The annotations in G are parsed next. To this end, canonical RDF parsing uses a function ANN that assigns a set of annotations ANN(x) to each URI reference or a blank node x. This function is initialized by setting ANN(x) = ∅ for each each URI reference or a blank node x. Next, triple patters from the headers of Tables 9 and 10 are matched in G. For each matched pattern, ANN(x) is extended with all annotations from the right columns of the tables matching the respective conditions in the left columns. Each time one of these triple patterns is matched, the matched triples are removed from G. This process is repeated until no further matches are possible.
For each triple x *:y z in G where AP(*:y) ≠ ε, for each satisfied condition...  ...this annotation is added to ANN(x). 

z is a URI reference and CE(z) is a class  Annotation( *:y Class( CE(z) ) ) 
z is a URI reference and DR(z) is a datatype  Annotation( *:y Datatype( DR(z) ) ) 
z is a URI reference and OPE(z) is an object property  Annotation( *:y ObjectProperty( OPE(z) ) ) 
z is a URI reference and DPE(z) is a data property  Annotation( *:y DataProperty( DPE(z) ) ) 
z is a URI reference and AP(z) is an annotation property  Annotation( *:y AnnotationProperty( AP(z) ) ) 
z is a URI reference and CE(z), DR(z), OPE(z), DPE(z), and AP(z) are all equal to ε 
Annotation( *:y NamedIndividual( z ) ) 
z is blank node  Annotation( *:y z ) 
For each triple pattern in G of the form
_:w rdf:type owl:Annotation
such that AP(*:y) ≠ ε and_:w owl:subject x _:w owl:predicate *:y _:w owl:object z no triple in G contain _:w in subject or object position, for each satisfied condition... 
...this annotation is added to ANN(x). 

z is a URI reference and CE(z) is a class  Annotation( ANN(_:w) *:y Class( CE(z) ) ) 
z is a URI reference and DR(z) is a datatype  Annotation( ANN(_:w) *:y Datatype( DR(z) ) ) 
z is a URI reference and OPE(z) is an object property  Annotation( ANN(_:w) *:y ObjectProperty( OPE(z) ) ) 
z is a URI reference and DPE(z) is a data property  Annotation( ANN(_:w) *:y DataProperty( DPE(z) ) ) 
z is a URI reference and AP(z) is an annotation property  Annotation( ANN(_:w) *:y AnnotationProperty( AP(z) ) ) 
z is a URI reference and CE(z), DR(z), OPE(z), DPE(z), and AP(z) are all equal to ε 
Annotation( ANN(_:w) *:y NamedIndividual( z ) ) 
z is blank node  Annotation( ANN(_:w) *:y z ) 
Let x be the node that is matched to *:x or _:x while parsing the ontology header of O according to the patterns from Table 4. Then, ANN(x) determines the set of ontology annotations of O.
Next, the functions OPE, DR, and CE are extended as shown in Tables 11, 12, and 13, as well as in Tables 14 and 15. The patterns in the latter two tables are not generated by the mapping from Section 2, but they can be present in RDF graphs that encode OWL DL ontologies. Each time a pattern is matched, the matched triples are removed from G. Pattern matching is repeated until no triple pattern can be matched to G.
If G contains this pattern...  ...then OPE(_:x) is set to this object property expression. 

_:x owl:inverseOf *:y { OPE(_:x) = ε and OPE(*:y) ≠ ε } 
InverseOf( OPE(*:y) ) 
If G contains this pattern...  ...then DR(_:x) is set to this data range. 

_:x rdf:type rdfs:Datatype _:x owl:datatypeComplementOf y { DR(y) ≠ ε } 
ComplementOf( DR(y) ) 
_:x rdf:type rdfs:Datatype _:x owl:oneOf T(SEQ lt_{1} ... lt_{n}) { n ≥ 1 } 
OneOf( lt_{1} ... lt_{n} ) 
_:x rdf:type rdfs:Datatype _:x owl:onDatatype *:y _:x owl:withRestrictions T(SEQ _:z_{1} ... _:z_{n}) _:z_{1} f_{1} lt_{1} ... _:z_{n} f_{n} lt_{n} { DR(*:y) is a datatype } 
DatatypeRestriction( DR(*:y) f_{1} lt_{1} ... f_{n} lt_{n} ) 
If G contains this pattern...  ...then CE(_:x) is set to this class expression. 

_:x rdf:type owl:Class _:x owl:complementOf y { CE(y) ≠ ε } 
ComplementOf( CE(y) ) 
_:x rdf:type owl:Class _:x owl:unionOf T(SEQ y_{1} ... y_{n}) { n ≥ 2 and CE(y_{i}) ≠ ε for each 1 ≤ i ≤ n } 
UnionOf( CE(y_{1}) ... CE(y_{n}) ) 
_:x rdf:type owl:Class _:x owl:intersectionOf T(SEQ y_{1} ... y_{n}) { n ≥ 2 and CE(y_{i}) ≠ ε for each 1 ≤ i ≤ n } 
IntersectionOf( CE(y_{1}) ... CE(y_{n}) ) 
_:x rdf:type owl:Class _:x owl:oneOf T(SEQ *:y_{1} ... *:y_{n}) { n ≥ 1 } 
OneOf( *:y_{1} ... *:y_{n} ) 
_:x rdf:type owl:SelfRestriction _:x owl:onProperty y { OPE(y) ≠ ε } 
ExistsSelf( OPE(y) ) 
_:x rdf:type owl:Restriction _:x owl:onProperty y _:x owl:hasValue *:z { OPE(y) ≠ ε } 
HasValue( OPE(y) *:z ) 
_:x rdf:type owl:Restriction _:x owl:onProperty y _:x owl:someValuesFrom z { OPE(y) ≠ ε and CE(z) ≠ ε } 
SomeValuesFrom( OPE(y) CE(z) ) 
_:x rdf:type owl:Restriction _:x owl:onProperty y _:x owl:allValuesFrom z { OPE(y) ≠ ε and CE(z) ≠ ε } 
AllValuesFrom( OPE(y) CE(z) ) 
_:x rdf:type owl:Restriction _:x owl:minQualifiedCardinality NN_INT(n) _:x owl:onProperty y _:x owl:onClass z { OPE(y) ≠ ε and CE(z) ≠ ε } 
MinCardinality( n OPE(y) CE(z) ) 
_:x rdf:type owl:Restriction _:x owl:maxQualifiedCardinality NN_INT(n) _:x owl:onProperty y _:x owl:onClass z { OPE(y) ≠ ε and CE(z) ≠ ε } 
MaxCardinality( n OPE(y) CE(z) ) 
_:x rdf:type owl:Restriction _:x owl:qualifiedCardinality NN_INT(n) _:x owl:onProperty y _:x owl:onClass z { OPE(y) ≠ ε and CE(z) ≠ ε } 
ExactCardinality( n OPE(y) CE(z) ) 
_:x rdf:type owl:Restriction _:x owl:minCardinality NN_INT(n) _:x owl:onProperty y { OPE(y) ≠ ε } 
MinCardinality( n OPE(y) ) 
_:x rdf:type owl:Restriction _:x owl:maxCardinality NN_INT(n) _:x owl:onProperty y { OPE(y) ≠ ε } 
MaxCardinality( n OPE(y) ) 
_:x rdf:type owl:Restriction _:x owl:cardinality NN_INT(n) _:x owl:onProperty y { OPE(y) ≠ ε } 
ExactCardinality( n OPE(y) ) 
_:x rdf:type owl:Restriction _:x owl:onProperty y _:x owl:hasValue lt { DPE(y) ≠ ε } 
HasValue( DPE(y) lt ) 
_:x rdf:type owl:Restriction _:x owl:onProperty y _:x owl:someValuesFrom z { DPE(y) ≠ ε and DR(z) ≠ ε } 
SomeValuesFrom( DPE(y) DR(z) ) 
_:x rdf:type owl:Restriction _:x owl:onProperties T(SEQ y_{1} ... y_{n}) _:x owl:someValuesFrom z { DPE(y_{i}) ≠ ε for each 1 ≤ i ≤ n and DR(z) ≠ ε } 
SomeValuesFrom( DPE(y_{1}) ... DPE(y_{n}) DR(z) ) 
_:x rdf:type owl:Restriction _:x owl:onProperty y _:x owl:allValuesFrom z { DPE(y) ≠ ε and DR(z) ≠ ε } 
AllValuesFrom( DPE(y) DR(z) ) 
_:x rdf:type owl:Restriction _:x owl:onProperties T(SEQ y_{1} ... y_{n}) _:x owl:allValuesFrom z { DPE(y_{i}) ≠ ε for each 1 ≤ i ≤ n and DR(z) ≠ ε } 
AllValuesFrom( DPE(y_{1}) ... DPE(y_{n}) DR(z) ) 
_:x rdf:type owl:Restriction _:x owl:minQualifiedCardinality NN_INT(n) _:x owl:onProperty y _:x owl:onDataRange z { DPE(y) ≠ ε and DR(z) ≠ ε } 
MinCardinality( n DPE(y) DR(z) ) 
_:x rdf:type owl:Restriction _:x owl:maxQualifiedCardinality NN_INT(n) _:x owl:onProperty y _:x owl:onDataRange z { DPE(y) ≠ ε and DR(z) ≠ ε } 
MaxCardinality( n DPE(y) DR(z) ) 
_:x rdf:type owl:Restriction _:x owl:qualifiedCardinality NN_INT(n) _:x owl:onProperty y _:x owl:onDataRange z { DPE(y) ≠ ε and DR(z) ≠ ε } 
ExactCardinality( n DPE(y) DR(z) ) 
_:x rdf:type owl:Restriction _:x owl:minCardinality NN_INT(n) _:x owl:onProperty y { DPE(y) ≠ ε } 
MinCardinality( n DPE(y) ) 
_:x rdf:type owl:Restriction _:x owl:maxCardinality NN_INT(n) _:x owl:onProperty y { DPE(y) ≠ ε } 
MaxCardinality( n DPE(y) ) 
_:x rdf:type owl:Restriction _:x owl:cardinality NN_INT(n) _:x owl:onProperty y { DPE(y) ≠ ε } 
ExactCardinality( n DPE(y) ) 
If G contains this pattern...  ...then DR(_:x) is set to this object property expression. 

_:x rdf:type owl:DataRange _:x owl:oneOf T(SEQ lt_{1} ... lt_{n}) { n ≥ 1 } 
OneOf( lt_{1} ... lt_{n} ) 
_:x rdf:type owl:DataRange _:x owl:oneOf T(SEQ) 
ComplementOf( rdfs:Literal ) 
If G contains this pattern...  ...then CE(_:x) is set to this class expression. 

_:x rdf:type owl:Class _:x owl:unionOf T(SEQ) 
owl:Nothing 
_:x rdf:type owl:Class _:x owl:unionOf T(SEQ y) { CE(y) ≠ ε } 
CE(y) 
_:x rdf:type owl:Class _:x owl:intersectionOf T(SEQ) 
owl:Thing 
_:x rdf:type owl:Class _:x owl:intersectionOf T(SEQ y) { CE(y) ≠ ε } 
CE(y) 
_:x rdf:type owl:Class _:x owl:oneOf T(SEQ) 
owl:Nothing 
The ontology O is then populated with axioms. The patterns from Table 16 are matched in G, the resulting axioms are added to O. Each time a pattern is matched, the matched triples are removed from G. The patterns for the EntityAnnotation and AnonymousIndividualAnnotation axioms can be matched to the empty set of triples so, in order to prevent infinite matches of the same pattern, these patterns are are matched to G at most once for each different URI reference *:x or blank node _:x.
If G contains this pattern...  ...then the following axiom is added to O. 

*:x rdf:type owl:Class  Declaration( Class( *:x ) ) 
*:x rdf:type rdfs:Datatype  Declaration( Datatype( *:x ) ) 
*:x rdf:type owl:ObjectProperty  Declaration( ObjectProperty( *:x ) ) 
*:x rdf:type owl:DatatypeProperty  Declaration( DataProperty( *:x ) ) 
*:x rdf:type owl:AnnotationProperty  Declaration( AnnotationProperty( *:x ) ) 
*:x rdf:type owl:NamedIndividual  Declaration( NamedIndividual( *:x ) ) 
[ *:x rdf:type owl:DeprecatedClass ] { CE(*:x) ≠ ε, and ANN(*:x) ≠ ∅ or the optional triple is matched } 
EntityAnnotation( Class( *:x ) ANN(*:x) [ Deprecated ] ) 
[ *:x rdf:type owl:DeprecatedClass ] { DR(*:x) ≠ ε, and ANN(*:x) ≠ ∅ or the optional triple is matched } 
EntityAnnotation( Datatype( *:x ) ANN(*:x) [ Deprecated ] ) 
[ *:x rdf:type owl:DeprecatedProperty ] { OPE(*:x) ≠ ε, and ANN(*:x) ≠ ∅ or the optional triple is matched } 
EntityAnnotation( ObjectProperty( *:x ) ANN(*:x) [ Deprecated ] ) 
[ *:x rdf:type owl:DeprecatedProperty ] { DPE(*:x) ≠ ε, and ANN(*:x) ≠ ∅ or the optional triple is matched } 
EntityAnnotation( DataProperty( *:x ) ANN(*:x) [ Deprecated ] ) 
[ *:x rdf:type owl:DeprecatedProperty ] { AP(*:x) ≠ ε, and ANN(*:x) ≠ ∅ or the optional triple is matched } 
EntityAnnotation( AnnotationProperty( *:x ) ANN(*:x) [ Deprecated ] ) 
{ CE(*:x) ≠ ε, DR(*:x) ≠ ε, OPE(*:x) ≠ ε, DPE(*:x) ≠ ε, AP(*:x) ≠ ε, and ANN(*:x) ≠ ∅ } 
EntityAnnotation( Individual( *:x ) ANN(*:x) ) 
{ ANN(_:x) ≠ ∅ }  AnonymousIndividualAnnotation( _:x ANN(_:x) ) 
x rdfs:subClassOf y { CE(x) ≠ ε and CE(y) ≠ ε } 
SubClassOf( CE(x) CE(y) ) 
x owl:equivalentClass y { CE(x) ≠ ε and CE(y) ≠ ε } 
EquivalentClasses( CE(x) CE(y) ) 
x owl:disjointWith y { CE(x) ≠ ε and CE(y) ≠ ε } 
DisjointClasses( CE(x) CE(y) ) 
_:x rdf:type owl:AllDisjointClasses _:x owl:members T(SEQ y_{1} ... y_{n}) { n ≥ 2 and CE(y_{i}) ≠ ε for each 1 ≤ i ≤ n } 
DisjointClasses( CE(y_{1}) ... CE(y_{n}) ) 
x owl:disjointUnionOf T(SEQ y_{1} ...
y_{n}) { n ≥ 2, CE(x) ≠ ε, and CE(y_{i}) ≠ ε for each 1 ≤ i ≤ n } 
DisjointUnion( CE(x) CE(y_{1}) ... CE(y_{n}) ) 
x rdfs:subPropertyOf y { OPE(x) ≠ ε and OPE(y) ≠ ε } 
SubPropertyOf( OPE(x) OPE(y) ) 
_:x rdfs:subPropertyOf y _:x owl:propertyChain T(SEQ x_{1} ... x_{n}) { n ≥ 2, OPE(x_{i}) ≠ ε for each 1 ≤ i ≤ n, and OPE(y) ≠ ε } 
SubPropertyOf( PropertyChain( OPE(x_{1}) ... OPE(x_{n}) ) OPE(y) ) 
x owl:equivalentProperty y { OPE(x) ≠ ε and OPE(y) ≠ ε } 
EquivalentProperties( OPE(x) OPE(y) ) 
x owl:propertyDisjointWith y { OPE(x) ≠ ε and OPE(y) ≠ ε } 
DisjointProperties( OPE(x) OPE(y) ) 
_:x rdf:type owl:AllDisjointProperties _:x owl:members T(SEQ y_{1} ... y_{n}) { n ≥ 2 and OPE(y_{i}) ≠ ε for each 1 ≤ i ≤ n } 
DisjointProperties( OPE(y_{1}) ... OPE(y_{n}) ) 
x rdfs:domain y { OPE(x) ≠ ε and CE(y) ≠ ε } 
PropertyDomain( OPE(x) CE(y) ) 
x rdfs:range y { OPE(x) ≠ ε and CE(y) ≠ ε } 
PropertyRange( OPE(x) CE(y) ) 
x owl:inverseOf y { OPE(x) ≠ ε and OPE(y) ≠ ε } 
InverseProperties( OPE(x) OPE(y) ) 
x rdf:type owl:FunctionalProperty { OPE(x) ≠ ε } 
FunctionalProperty( OPE(x) ) 
x rdf:type owl:InverseFunctionalProperty { OPE(x) ≠ ε } 
InverseFunctionalProperty( OPE(x) ) 
x rdf:type owl:ReflexiveProperty { OPE(x) ≠ ε } 
ReflexiveProperty( OPE(x) ) 
x rdf:type owl:IrreflexiveProperty { OPE(x) ≠ ε } 
IrreflexiveProperty( OPE(x) ) 
x rdf:type owl:SymmetricProperty { OPE(x) ≠ ε } 
SymmetricProperty( OPE(x) ) 
x rdf:type owl:AsymmetricProperty { OPE(x) ≠ ε } 
AsymmetricProperty( OPE(x) ) 
x rdf:type owl:TransitiveProperty { OPE(x) ≠ ε } 
TransitiveProperty( OPE(x) ) 
x rdfs:subPropertyOf y { DPE(x) ≠ ε and DPE(y) ≠ ε } 
SubPropertyOf( DPE(x) DPE(y) ) 
x owl:equivalentProperty y { DPE(x) ≠ ε and DPE(y) ≠ ε } 
EquivalentProperties( DPE(x) DPE(y) ) 
x owl:propertyDisjointWith y { DPE(x) ≠ ε and DPE(y) ≠ ε } 
DisjointProperties( DPE(x) DPE(y) ) 
_:x rdf:type owl:AllDisjointProperties _:x owl:members T(SEQ y_{1} ... y_{n}) { n ≥ 2 and DPE(y_{i}) ≠ ε for each 1 ≤ i ≤ n } 
DisjointProperties( DPE(y_{1}) ... DPE(y_{n}) ) 
x rdfs:domain y { DPE(x) ≠ ε and CE(y) ≠ ε } 
PropertyDomain( DPE(x) CE(y) ) 
x rdfs:range y { DPE(x) ≠ ε and DR(y) ≠ ε } 
PropertyRange( DPE(x) DR(y) ) 
x rdf:type owl:FunctionalProperty { DPE(x) ≠ ε } 
FunctionalProperty( DPE(x) ) 
x owl:hasKey T(SEQ y_{1} ...
y_{n}) { n ≥ 1, CE(x) ≠ ε, and OPEorDPE(y_{i}) ≠ ε for each 1 ≤ i ≤ n } 
HasKey( CE(x) OPEorDPE(y_{1}) ... OPEorDPE(y_{n}) ) 
x owl:sameAs y  SameIndividual( x y ) 
x owl:differentFrom y  DifferentIndividuals( x y ) 
_:x rdf:type owl:AllDifferent _:x owl:members T(SEQ x_{1} ... x_{n}) { n ≥ 2 } 
DifferentIndividuals( x_{1} ... x_{n} ) 
_:x rdf:type owl:AllDifferent _:x owl:distinctMembers T(SEQ x_{1} ... x_{n}) { n ≥ 2 } 
DifferentIndividuals( x_{1} ... x_{n} ) 
x rdf:type y { CE(y) ≠ ε } 
ClassAssertion( x CE(y) ) 
x *:y z { OPE(*:y) ≠ ε } 
PropertyAssertion( OPE(*:y) x z ) 
_:x rdf:type owl:NegativePropertyAssertion _:x owl:sourceIndividual w _:x owl:assertionProperty y _:x owl:targetIndividual z { OPE(y) ≠ ε } 
NegativePropertyAssertion( OPE(y) w z ) 
x *:y lt { DPE(*:y) ≠ ε } 
PropertyAssertion( DPE(*:y) x lt ) 
_:x rdf:type owl:NegativePropertyAssertion _:x owl:sourceIndividual w _:x owl:assertionProperty y _:x owl:targetValue lt { DPE(y) ≠ ε } 
NegativePropertyAssertion( DPE(y) w lt ) 
For clarity, Table 16 handles only axioms without annotations. In case of the patterns for owl:AllDisjointClasses, owl:AllDisjointProperties, owl:AllDifferent, and owl:NegativePropertyAssertion, axiom annotations are defined by ANN(_:x). For other axioms, axiom annotations are obtained by additionally matching patterns from Table 17 in G during axiom matching. Each time a triple pattern is matched, the matched triples are removed from G.
If G contains this pattern...  ...then the following axiom is added to O. 

_:x rdf:type owl:Axiom _:x owl:subject s _:x owl:predicate *:p _:x owl:object o { s *:p o is the main triple for an axiom and G contains possible necessary side triples for the axiom } 
The result is the axiom corresponding to s *:p o (and possible side triples) that additionally contains the annotations ANN(_:x). 
Finally, the patterns from Table 18 are matched in G, the resulting axioms are added to O. These patterns are not generated by the mapping from Section 2, but they can be present in RDF graphs that encode OWL DL ontologies. (Note that the patterns from the table do not contain triples of the form *:x rdf:type owl:Class because such triples are removed while parsing the entity declarations, as specified in Section 3.1.) Each time a triple pattern is matched, the matched triples are removed from G.
If G contains this pattern...  ...then the following axiom is added to O. 

*:x owl:complementOf y { CE(*:x) ≠ ε and CE(y) ≠ ε } 
EquivalentClasses( CE(*:x) ComplementOf( CE(y) ) ) 
*:x owl:unionOf T(SEQ) { CE(*:x) ≠ ε } 
EquivalentClasses( CE(*:x) owl:Nothing ) 
*:x owl:unionOf T(SEQ y_{1}) { CE(*:x) ≠ ε and CE(y_{1}) ≠ ε } 
EquivalentClasses( CE(*:x) CE(y) ) 
*:x owl:unionOf T(SEQ y_{1} ...
y_{n}) { n ≥ 2, CE(*:x) ≠ ε, and CE(y_{i}) ≠ ε for each 1 ≤ i ≤ n } 
EquivalentClasses( CE(*:x) UnionOf( CE(y_{1}) ... CE(y_{n}) ) ) 
*:x owl:intersectionOf T(SEQ) { CE(*:x) ≠ ε } 
EquivalentClasses( CE(*:x) owl:Thing ) 
*:x owl:intersectionOf T(SEQ y_{1}) { CE(*:x) ≠ ε and CE(y_{1}) ≠ ε } 
EquivalentClasses( CE(*:x) CE(y) ) 
*:x owl:intersectionOf T(SEQ y_{1} ...
y_{n}) { n ≥ 2, CE(*:x) ≠ ε, and CE(y_{i}) ≠ ε for each 1 ≤ i ≤ n } 
EquivalentClasses( CE(*:x) IntersectionOf( CE(y_{1}) ... CE(y_{n}) ) ) 
*:x owl:oneOf T(SEQ) { CE(*:x) ≠ ε } 
EquivalentClasses( CE(*:x) owl:Nothing ) 
*:x owl:oneOf T(SEQ *:y_{1} ...
*:y_{n}) { CE(*:x) ≠ ε } 
EquivalentClasses( CE(*:x) OneOf( *:y_{1} ... *:y_{n} ) ) 
At the end of this process, if G is not empty then G MUST be rejected as syntactically incorrect.